A multi-stage gearbox having nine forward gears and having one reverse gear is known from DE 10 2008 000 429 A1. The multi-stage gearbox includes four planetary sets, eight rotatable shafts and six shift elements. The first and the second planetary set form a shiftable upstream gear set, whereas the third and the fourth planetary sets constitute a so-called main gear set. The carrier plates or webs of the first and second planetary sets are coupled to one another by one of the rotatable shafts, which is connected to an element of the main gear set. The ring gear of the first planetary set is coupled to the sun gear of the second planetary set with a further shaft of the rotatable shafts, which is detachably connectable to a drive shaft with a clutch.
The sun gear of the first planetary set is couplable via a further shaft of the rotatable shafts to a housing of the multi-stage gearbox through a brake and is connectable to the drive shaft with a clutch. The ring gear of the second planetary set is couplable via a shaft to the housing through a brake. In turn, a further shaft of the rotatable shafts is connected at least to one element of the main gear set and is couplable through the brake to the housing. A further shaft of the rotatable shafts is connected to a further element of the main gear set and is connectable to the drive shaft through a shift element in the form of a clutch, whereas a drive output shaft is connected to at least one further element of the main gear set. At least two of the shift elements of the multi-stage gearbox are in the form of positively engaging shift elements, which are deactivated only during upshifts.
To save fuel, vehicles are equipped with so-called engine start-stop functions. In vehicle ranges close to standstill, these functions and certain actuation logic allow for a drive machine to be transferred into a shut-down operating state. Here, through engine start-stop functions, it is sought for the power flow between the drive machine and the drive output of the vehicle to be produced within short operating times in the region of a gearbox upon starting of the engine.